1. Field of Invention
This invention relates to the field of pull-type farm implements and, more particularly, to a swivel drawbar hitch mechanism for establishing a draft connection between the pulling tractor and the pull-type implement.
2. Description of Related Art
Agricultural pull-type implements are generally towed by a tractor using a hitch assembly coupled to a drawbar of the tractor. Swivel hitch assemblies desirably allow for relative movement of the pull-type implement with respect to the tractor, such as when turning corners or travelling over uneven surfaces. During such movements, the hitch assembly may be subject to various loads.
One example of a swivel drawbar hitch includes a gearbox assembly having a lower right-angle gearbox and an upper right angle gearbox that swivels about an upright axis relative to the lower right angle gearbox. The upper and lower right angle gearboxes share a common upright drive shaft that couples an input, U-joint driveline assembly (e.g., components conveying power from a power take-off residing at the tractor to the lower right angle gearbox) to an output, U-joint driveline assembly extending from the upper right angle gearbox to the pull-type implement. However, all the draft loads of the pull-type implement are carried through the swivel gearbox. As implements get larger and are designed to travel at faster speeds through the field and on the road, the draft loads increase. This can lead to wear and accelerate the failure of one or more components of the hitch assembly.